Remote management problem

I have a lab of PC’s that all work fine exept one. I cannot remotley access theis one PC at all from the DC logged in as the Administrator. The machine is properly joined to the domain, and everyhing outgoing works fine. I tried plugging it into theport for the PC next to it, and I was able to manage it remotly, and access the drive. I then re-terminated both ends of the run and re-certified it, and it still did not work. I then ran a new cable, terminated it into a different port ont he patchpanel and used a ner Cat5e connector on the PC end, certified it, and it still doesn’t work, even with a new run. I also tried new patch cords. Anyone have any idea what’s going on?